Joret line

The Joret line (French: ligne Joret; Norman: lène Joret: Picard: line Joret) is an isogloss that divides the langues d'oïl. Dialects north and west of it preserve Latin /k/ and /ɡ/ before /a/; dialects south and east of it palatalize them. In Old French the result of this palatalisation was /t͡ʃ/ and /d͡ʒ/ (for original /k/ and /ɡ/ respectively), which yield /ʃ/ and /ʒ/ in Modern French. The line was first identified by Charles Joret and published in 1883.

The area north and west of it is sometimes called the 'Normano-Picard domain' (French: domaine normano-picard). Within it lie Picard and the northern dialects of Norman.